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authorAlexandre Courbot <acourbot@nvidia.com>2015-08-17 17:23:52 +0900
committerLinus Walleij <linus.walleij@linaro.org>2015-08-17 10:56:24 +0200
commit7fa25937542358bfa01ef5c5a1e9a00bd164c000 (patch)
treed4edc6026912b6b8ad9450aa84f26f06d4b23794
parentac49fbd1f9d437cca7234473850aef4165779383 (diff)
gpio/grgpio: fix deadlock in grgpio_irq_unmap()
As reported by Alexey Khoroshilov: grgpio_irq_unmap() code looks quite suspicious regarding usage of priv->bgc.lock spinlock. It locks the spinlock in line 310: spin_lock_irqsave(&priv->bgc.lock, flags); and then it can call grgpio_set_imask() in line 317: grgpio_set_imask(priv, i, 0); But grgpio_set_imask() unconditionally locks the spinlock by itself. Fix this by moving the spinlock acquisition outside of grgpio_set_imask(). Found by Linux Driver Verification project (linuxtesting.org). Reported-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Cc: Alexey Khoroshilov <khoroshilov@ispras.ru> Cc: Andreas Larsson <andreas@gaisler.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
-rw-r--r--drivers/gpio/gpio-grgpio.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/gpio/gpio-grgpio.c b/drivers/gpio/gpio-grgpio.c
index 77053d6..801423f 100644
--- a/drivers/gpio/gpio-grgpio.c
+++ b/drivers/gpio/gpio-grgpio.c
@@ -104,17 +104,12 @@ static void grgpio_set_imask(struct grgpio_priv *priv, unsigned int offset,
{
struct bgpio_chip *bgc = &priv->bgc;
unsigned long mask = bgc->pin2mask(bgc, offset);
- unsigned long flags;
-
- spin_lock_irqsave(&bgc->lock, flags);
if (val)
priv->imask |= mask;
else
priv->imask &= ~mask;
bgc->write_reg(priv->regs + GRGPIO_IMASK, priv->imask);
-
- spin_unlock_irqrestore(&bgc->lock, flags);
}
static int grgpio_to_irq(struct gpio_chip *gc, unsigned offset)
@@ -180,16 +175,26 @@ static void grgpio_irq_mask(struct irq_data *d)
{
struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
int offset = d->hwirq;
+ unsigned long flags;
+
+ spin_lock_irqsave(&priv->bgc.lock, flags);
grgpio_set_imask(priv, offset, 0);
+
+ spin_unlock_irqrestore(&priv->bgc.lock, flags);
}
static void grgpio_irq_unmask(struct irq_data *d)
{
struct grgpio_priv *priv = irq_data_get_irq_chip_data(d);
int offset = d->hwirq;
+ unsigned long flags;
+
+ spin_lock_irqsave(&priv->bgc.lock, flags);
grgpio_set_imask(priv, offset, 1);
+
+ spin_unlock_irqrestore(&priv->bgc.lock, flags);
}
static struct irq_chip grgpio_irq_chip = {